Airbag device

ABSTRACT

An airbag device includes an airbag formed with a discharge portion. The discharge portion includes: an opening portion; a tack portion around the opening portion; and a regulating belt portion disposed on a peripheral edge of the opening portion to regulate opening and closing of the opening portion. When the inflation of the airbag is completed, the tack portion is maintained in a folded state by the regulating belt portion due to tension acting on the regulation belt portion, so that a closed state of the opening portion is capable of being maintained, and when the tension does not act on the regulating belt portion, the folded state is released and the opening portion is brought into an open state.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromprior Japanese patent application No. 2019-140318, filed on Jul. 30,2019, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to an airbag device that includes anairbag folded and stored in a storage part, configured to inflate so asto protrude from the storage part by allowing inflation gas to flowinside, and including a discharge portion capable of discharging a partof the inflation gas flowing into the airbag.

BACKGROUND ART

In the related art, in an airbag including a discharge portion capableof discharging a part of inflation gas flowing inside, the dischargeportion includes an opening portion formed by cutting out a basematerial in a region of a tack portion provided so as to form a fold onthe base material forming the airbag, and two regulating belt portionsextending from both sides of the opening portion. The regulating beltportion has a tip end side connected to the airbag, and unfold the foldof the tack portion and opens the opening portion when receiving anoccupant and relaxing (for example, see JP-A-2017-177845).

However, in the related-art airbag, the regulating belt portions aredisposed on both sides of the opening portion, and a region of a baseportion side connected to the tack portion is disposed on an outersurface side of the airbag, a tip end is away from the base portionside, separated from the tack portion, and connected to a locationcloser to a center side of the airbag than the tack portion region. Whentension is generated in the regulating belt portion at the time ofcompletion of the inflation of the airbag, the regulating belt portionbehaves in a manner of pulling inward the fold part disposed on an innerperipheral surface side of the airbag in the tack portion. Therefore, inthe related-art airbag device, even if the tack portion receives theinternal pressure of the inflation gas flowing inside, a part disposedin the middle is pulled by the regulating belt portion and behaves as ifbeing peeled off from a part disposed on an outer peripheral surfaceside. There is room for improvement in that the opening portion isstably closed by the tack portion.

The present invention solves the above-described problem, and an objectthereof is to provide an airbag device capable of accurately controllingan internal pressure of an airbag when inflation is completed by adischarge portion.

SUMMARY OF INVENTION

According to an aspect of the invention, there is provided an airbagdevice comprising: an airbag folded and stored in a storage part,configured to inflate so as to protrude from the storage part byallowing inflation gas to flow inside, the airbag formed with adischarge portion capable of discharging a part of the inflation gasflowing into the airbag, wherein the discharge portion includes: anopening portion formed by cutting out a base material forming theairbag; a tack portion provided on the base material around the openingportion; and a regulating belt portion separated from the airbag anddisposed on a peripheral edge of the opening portion to regulate openingand closing of the opening portion, the tack portion is formed by makinga fold on the base material from a state where the base material isflatly unfolded so as to reduce an opening area of an opening on theopening portion, the tack portion is formed by folding the base materialby an outer fold and an inner fold that which are formed substantiallyin parallel, such that an inner region, an intermediate region, and anouter region are stacked, a base end side of the regulating belt portionis coupled to an outer region side, the regulating belt portion isdisposed to be substantially orthogonal to the outer fold and the innerfold, and a tip end side inserted into the airbag is connected to a sideof the airbag which is further away from a part coupled to the base endin a state where the regulating belt portion is in an inverted state soas to surround the tack portion such that the regulating belt portion isinserted into an insertion hole formed on a part of the base materialdisposed continuously from the inner region, and when the inflation ofthe airbag is completed, the tack portion is maintained in a foldedstate by the regulating belt portion due to tension acting on theregulation belt portion, so that a closed state of the opening portionis capable of being maintained, and when the tension does not act on theregulating belt portion, the folded state is released and the openingportion is brought into an open state.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view showing the vicinity where an airbag devicefor a passenger seat according to an embodiment of the present inventionis mounted.

FIG. 2 is a schematic enlarged sectional view of the airbag deviceaccording to the embodiment along a front-rear direction.

FIG. 3 is a schematic perspective view of an airbag used in the airbagdevice according to the embodiment in a state of being inflated alone asviewed from a front left side.

FIG. 4 is a schematic perspective sectional view of the airbag in FIG. 3as viewed from a rear right side.

FIG. 5 is a schematic longitudinal sectional view of the airbag in FIG.3, and a sectional view at a central part of a rear side wall portion ina left-right direction.

FIG. 6 is a schematic longitudinal sectional view of the airbag in FIG.3, and a sectional view at a part of a restraining recess.

FIG. 7 is a schematic cross-sectional view of the airbag in FIG. 3.

FIG. 8 is a plan view showing base materials forming the airbag in FIG.3.

FIG. 9 is a plan view showing the rest of the base materials forming theairbag in FIG. 3.

FIG. 10 is an enlarged plan view of a left panel portion.

FIGS. 11A and 11B are schematic plan views showing a state where a tackportion is formed on the left panel portion.

FIG. 12 is a schematic cross-sectional view showing state where theairbag is completely inflated in the airbag device according to theembodiment.

FIGS. 13A and 13B are schematic sectional views of a part of a dischargeportion of the airbag when the inflation is completed in the airbagdevice according to the embodiment, and show a state in a closed modeand a state in an open mode.

FIG. 14A and 14B are schematic sectional views of the airbag when theinflation is completed in the airbag device according to the embodiment,and show a state in the closed mode and a state in the open mode.

FIGS. 15A and 15B are schematic cross-sectional views of an airbagaccording to another embodiment of the present invention, and show astate in the closed mode and a state in the open mode.

FIG. 16 is a schematic sectional view of a part of a discharge portionwhen the inflation is completed in an airbag according to a comparativeexample.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the present invention will be describedwith reference to the drawings. In the embodiment, an airbag device fora passenger seat will be described as an example of an airbag device. Asshown in FIGS. 1, 2 and 12, an airbag device M for a passenger seat(hereinafter, referred to as “airbag device”) includes a folded airbag25, an inflator 8 supplying inflation gas to the airbag 25, a case 12 asa storage part storing and holding the airbag 25 and the inflator 8, aretainer 9 for attaching the airbag 25 and the inflator 8 to the case12, an airbag cover 6 covering the folded airbag 25, and a lockingmember 16 locking tip ends 65 b of regulating belt portions 65 that forma discharge portion 50 formed in the airbag 25. In the case of theembodiment, operations of the inflator 8 and the locking member 16 arecontrolled by a control device 120 shown in FIG. 1.

As shown in FIG. 1, the control device 120 operates the inflator 8 byinputting electric signals from a position detection sensor 121 capableof detecting the physique of an occupant MP sitting on a passenger seatPS, a separation distance between an instrument panel 1 and the occupantMP, a weight detection sensor 122 capable of detecting the weight of theoccupant MP and a collision detection sensor 123 capable of detecting anacceleration and a direction of acceleration of a vehicle V and thelike, and controls the operation of the locking member 16 such that theairbag 25 is inflated in a suitable inflation mode.

The airbag cover 6 is integrally formed with the instrument panel 1 madeof synthetic resin, and includes two door portions 6 a, 6 b which areopened by being pushed by the airbag 25 when the airbag 25 is unfoldedand inflated. A connecting wall portion 6 c connected to a peripheralwall portion 14 of the case 12 is formed around the door portions 6 a, 6b in the airbag cover 6.

As shown in FIGS. 1 and 2, the inflator 8 includes a substantiallycylindrical body portion 8 a including a plurality of gas dischargeports 8 b, and a flange portion 8 c for attaching the inflator 8 to thecase 12. In the embodiment, the inflator 8 is controlled in operation bythe control device 120 so as to operate in a frontal collision, anoblique collision, and an offset collision of the vehicle V.

The case 12 as a storage part is formed in a substantially rectangularparallelepiped shape made of a sheet metal which has a rectangularopening on an upper end side of the case 12, and includes asubstantially rectangular bottom wall portion 13 to which the inflator 8is inserted and attached from below and peripheral wall portions 14which extend upward from an outer peripheral edge of the bottom wallportion 13 to lock the connecting wall portion 6 c of the airbag cover6. In the embodiment, the airbag 25 and the inflator 8 are connected tothe bottom wall portion 13 of the case 12 by causing bolts 9 a of theretainer 9 disposed in the airbag 25 as attachment units to pass througha peripheral edge of an inflow opening 34 in the airbag 25, the bottomwall portion 13 of the case 12 and the flange portion 8 c of theinflator 8 and fastening the bolts 9 a with nuts 10. Specifically, thecase 12 is configured to be wide in a left-right direction (see FIG.12), and an insertion hole into which the body portion 8 a of theinflator 8 can be inserted and insertion holes for inserting the bolls 9a of the retainer 9 are disposed at positions approximately at thecenter of the bottom wall portion 13 in the left-right direction(reference numerals are omitted). Further, in the bottom wall portion13, a through hole 13 a into which a tip end 65 b side of the regulatingbelt portion 65 described below can be inserted is formed on a left sideof the insertion hole for inserting the body portion 8 a of the inflator8 (see FIG. 2). The case 12 is connected to a body side of the vehicle Vby a bracket (not shown) formed on the bottom wall portion 13.

In the embodiment, the locking member 16 locking the tip end 65 h sideof the regulating belt portion 65 is disposed at a position below thebottom wall portion 13 of the case 12 and near the through hole 13 a(specifically, on a left side of the inflator 8). As shown in FIG. 2,the locking member 16 includes a locking pin 17 inserted into a lockinghole 66 which is formed on the tip end 65 b side of the regulating beltportion 65 and locks the tip end 65 b side of the regulating beltportion 65, an actuator 18 attached to a lower surface side of thebottom wall portion 13 and operating so as to be capable of pulling inthe locking pin 17, and a support bracket 19 configured to extenddownward from the bottom wall portion 13 at a tip end side of thelocking pin 17 and capable of supporting the tip end side of the lockingpin 17 The actuator 18 is configured to operate so as to pull in thelocking pin 17 by receiving an operation signal from the control device120. When the actuator 18 operates to pull in the locking pin 17, thelocking pin 17 shifts from a state of locking the tip end 65 b side ofthe regulating belt portion 65 to a state in which the locking isreleased, and the regulating belt portion 65 moves (see two-dot chainline in FIG. 2). If the actuator 18 can move the locking pin 17 by anelectric signal from the control device 120, a piston cylinder utilizingfluid pressures including a case where hydraulic pressure, waterpressure, pneumatic pressure, or gas pressure for inflating the inflatorand the like are generated, a motor utilizing the fluid pressures orelectricity, an electromagnetic solenoid, a spring utilizing an urgingforce at the time of restoration, and the like can be used. When theactuator 18 is not in operation, the tip end side of the locking pin 17is supported by the support bracket 19 so as to prevent a part on thetip end 65 b side of the regulating belt portion 65 from being pulledout of the locking pin 17 during locking.

As shown in FIGS. 3 to 7, the airbag 25 includes a bag body 26, arectifying cloth 74 disposed inside the bag body 26, tethers 77, 83, 84,90 disposed inside the bag body 26 and regulate an inflation completedshape of the bag body 26, and the regulating belt portions 65 extendingfrom the discharge portion 50 in the bag body 26.

The bag body 26 has a bag shape formed of a flexible sheet, and in thecase of the embodiment, as shown in FIGS. 3 to 7, the bag body 26includes a body inflation portion 27 and a protruding inflation portion41 disposed so as to partially protrude from a rear surface side of thebody inflation portion 27 when the inflation is completed. Theprotruding inflation portion 41 is disposed on a left end side when theinflation of the body inflation portion 27 is completed.

Since the body inflation portion 27 is disposed to fill a space betweenan upper surface 2 of the instrument panel 1 and the windshield 4 abovethe instrument panel 1 when the inflation is completed, the shape at thetime of completion of the inflation is a substantially quadrangularpyramid shape converging toward a front end side. The body inflationportion 27 includes a rear side wall portion 40 disposed on the rearsurface side which is an occupant MP side at the time of completion ofthe inflation, and a tapered peripheral wall portion 28 extendingforward from a peripheral edge of the rear side wall portion 40 andconverging toward the front end side. In the airbag 25 according theembodiment, the body inflation portion 27 is substantially symmetrical.

The peripheral wall portion 28 is a part disposed mainly between theinstrument panel 1 and the windshield 4 above the instrument panel 1when the inflation of the airbag 25 is completed, and includes an upperwall portion 29 and a lower wall portion 30 which are disposed to faceeach other in an upper-lower direction, and a left wall portion 31 and aright wall portion 32 which are disposed to face each other in theleft-right direction. On the lower surface side (lower wall portion 30side) on a front end side of the peripheral wall portion 28 (front end27 a side of the body inflation portion 27), an inflow opening 34 formedto be opened in a substantially circular shape to make the inflation gasflow therein, and a plurality of (in the case of the embodiment, four)mounting holes 35 for inserting the bolts 9 a of the retainer 9 at theperiphery edge of the inflow opening 34 are formed. On a left side ofthe inflow opening 34, a slit-shaped insertion hole 36 into which thetip end 65 b of the regulating belt portion 65 extending from thedischarge portion 50 can be inserted is formed substantially along theleft-right direction. Further, in the bag body 26 according to theembodiment, the left wall portion 31 of the peripheral wall portion 28is formed with the discharge portion 50 capable of discharging a part,of the inflation gas flowing inside. In the case of the embodiment, anopening portion 51 described below in the discharge portion 50 has anopening as a small open state even in a closed state, and an openingportion 51S in the small open state functions as a vent hole forexhausting excess inflation gas flowing inside. A vent hole 37 forexhausting the excess inflation gas flowing inside is formed to open ina substantially circular shape on the right wall portion 32. In the caseof the embodiment, the opening portion 51 formed on the left wallportion 31 and the vent hole 37 formed on the right wall portion 32 areconfigured such that the disposition positions substantially match whenviewed from the left-right direction, and are disposed at positionsbehind the center in the front-rear direction and slightly above thecenter in the upper-lower direction when viewed from the left-rightdirection. Further, an opening area of the vent hole 37 is configured tobe substantially the same as an opening area of the opening portion 51Sin the small open state.

The rear side wall portion 40 is disposed so as to be substantiallyalong the upper-lower direction on a rear surface side which is theoccupant MP side when the inflation of the airbag 25 is completed, andthe protruding inflation portion 41 which protrudes so as to partiallyprotrude rearward is disposed at a part on one end side in theleft-right direction (in the case of the embodiment, a left end sidewhich is a driver's seat side). In the rear side wall portion 40, aregion disposed on a right side of the protruding inflation portion 41constitutes a front collision restraint surface 43 capable of protectinga head MH of the occupant MP moving forward during the front collisionof the vehicle V.

The protruding inflation portion 41 is disposed in an upper region on anrear surface side of the body inflation portion 27 at the time of thecompletion of inflation, and is disposed at a left-oblique front side ofthe occupant MP sitting on the passenger seat PS when the inflation ofthe airbag 25 is completed (see FIG. 12). The protruding inflationportion 41 is configured to inflate by flowing an inflation gas into theinside through a front end side communicated with the body inflationportion 27, the outer shape at the time of completion of the inflationis a substantially plate-shaped shape disposed such that a thicknessdirection thereof extends along the left-right direction, and is asubstantially trapezoidal shape having a narrow width toward the rearend side when viewed from the left-right direction. The protrudinginflation portion 41 includes a left wall portion 41 a and a right wallportion 41 b which are arranged to face each other on the left and rightsides when the inflation is completed, and as shown in FIG. 7, the leftwall portion 41 a is configured to be connected to the left wall portion31 of the peripheral wall portion 28 in the body inflation portion 27.In the protruding inflation portion 41, the right wall portion 41 bconstitutes an oblique collision restraint surface 44 capable ofprotecting the head MH of the occupant MP that moves diagonally forwardat the time of an oblique collision or an offset collision of thevehicle V. The external dimension of the protruding inflation portion 41(width direction in the upper-lower direction and width direction in thefront-rear direction (protruding amount from the rear side wall portion40)) is set to a size that can accurately receive the head MH of theoccupant MP and smoothly guide the head MH to a restraining recess 45described below when the inflation of the airbag 25 is completed andcomes into contact with the head MH of the occupant MP moving diagonallyforward by the right wall portion 41 b (oblique collision restraintsurface 44).

In the airbag 25 according to the embodiment, the restraining recess 45is formed at a boundary between the protruding inflation portion 41 andthe rear side wall portion 40 (between the front collision restraintsurface 43 and the oblique collision restraint surface 44) to allow thehead MH of the occupant MP moving diagonally forward to enter and to berestrained. The restraining recess 45 is formed so as to extendsubstantially in the upper-lower direction at the boundary between theregion on the right side of the protruding inflation portion 41 and therear side wall portion 40 of the body inflation portion 27, and as shownin FIGS. 6 and 7, the restraining recess 45 has a configuration in whichthe rear end 45 b side is opened and recessed forward like a pocket. Therestraining recess 45 is widened up and down as viewed from theleft-right direction, and the outer peripheral edges of a left wallportion 46 and a right wall portion 47 having a substantiallytrapezoidal shape, which are slightly narrower toward the front end 45a, are continuously coupled (sewed) to each other except for the rearedge side. In the case of the embodiment, the restraining recess 45 hasa length dimension (opening width dimension) in the upper-lowerdirection of the part on the rear end 45 b side larger than a widthdimension in the upper-lower direction of the part on a front end sideof the protruding inflation portion 41, and the restraining recess 45 isformed so as to extend below the protruding inflation portion 41 (seeFIG. 6).

Further, in the airbag 25 according to the embodiment, the recessed tipend (front end 45 a) side of the restraining recess 45 is connected to atether 90 for a recess disposed in the bag body 26, and when theinflation of the airbag 25 is completed, the restraining recess 45 isdisposed in a state where the recessed tip end (front end 45 a) side ispulled forward by the tether 90 for a recess (see FIG. 7). In the caseof the embodiment, when the inflation of the airbag 25 is completed, therestraining recess 45 is connected to the right wall portion 41 b of theprotruding inflation portion 41 such that the left wall portion 46 andthe right wall portion 47 are in contact with each other oversubstantially the entire area, and is disposed slightly inclined withrespect to the front-rear direction such that the front end 45 a isdirected rightward.

The discharge portion 50 provided in the left wall portion 31 includesthe opening portion 51 formed by cutting out a left panel portion 99described below as a base material forming the airbag 25, a tack portion54 provided on the left panel portion 99 around the opening portion 51,and the regulating belt portions 65 separated from the bag body 26 (theairbag 25) and disposed on a peripheral edge of the opening portion 51to regulate opening and closing of the opening portion 51.

As shown in FIG. 10, the opening portion 51 includes an opening formingportion 52 formed in a substantially elliptical shape which is wide inthe front-rear direction when the left panel portion 99 is in a flatlyunfolded state. In detail, the opening shape of the opening formingportion 52 is substantially semicircular such that an upper edge 52 aand a lower edge 52 b are substantially parallel straight lines, and afront edge 52 c and a rear edge 52 d protrude in directions away fromeach other in the front-rear direction.

In the case of the embodiment, when the airbag 25 is completely inflatedin a state where the tip end 65 b side of the regulating belt portion 65is locked to the locking member 16, the tack portion 54 is disposed onthe left wall portion 31 so as to extend substantially along theupper-lower direction over substantially the entire upper-lower area(see FIGS. 3 and 14A). As shown in FIGS. 11A and 11 b, the tack portion54 is formed by folding the left panel portion 99 by an outer fold 56and an inner fold 57 formed substantially in parallel such that an innerregion 59, an intermediate region 60, and an outer region 61 from theinner peripheral side of the airbag 25 are sequentially stacked, and inthe case of the embodiment, the outer fold 56 and the inner fold 57forming the tack portion 54 are formed over the entire length of theleft panel portion 99, and are formed to be substantially orthogonal tothe opening forming portion 52 (specifically, the upper edge 52 a andthe lower edge 52 h of the opening forming portion 52) (see FIG. 10).Specifically, when the left panel portion 99 is in the flatly unfoldedstate, the outer fold 56, which is to be disposed on the outerperipheral surface side when the inflation of the airbag 25 iscompleted, is located near the front end of the opening forming portion52 and formed at a position behind the front edge 52 c of the formingportion 52, and the inner fold 57, which is to be disposed on the innerperipheral surface side when the inflation of the airbag 25 iscompleted, is formed substantially at the center of the opening formingportion 52 in the front-rear direction. In other words, an openingforming portion 42 forming the opening 51 is provided across the innerfold 57 and the outer fold 56.

The tack portion 54 includes an outer region 61 in front of the outerfold 56, an intermediate region 60 between the outer fold 56 and theinner fold 57, and an inner region 59 behind the inner fold 57, and thetack portion 54 is formed by laminating the inner region 59, theintermediate region 60, and the outer region 61 when the outer fold 56and the inner fold 57 are formed. At the time of forming the tackportion 54 in which the outer fold 56 and the inner fold 57 are formedin the left panel portion 99, the opening portion 51S is in a closedstate (small open state) as shown in FIG. 11A, and the opening area issmaller than that of the opening portion 51L (see FIG. 11B) in an openstate (large open state, approximately matching an external shape of theopening forming portion 52) in which the left panel portion 99 is in theflatly unfolded state (when the tack portion is not formed). Morespecifically, the opening area of the opening portion 51S in the closedstate (small open state) is made smaller than the opening area of theopening portion 51L in the open state (large open state) whichsubstantially matches an outer shape of the opening forming portion 52so as to make the front edge 52 c and the rear edge 52 d of the openingforming portion 52 close to each other (to reduce a width dimension inthe front-rear direction) In the case of the embodiment, the tackportion 54 is formed by sewing the folded edge portions together when anupper edge 99 a and a lower edge 99 b of the left panel portion 99 areconnected to a left edge 97 c of the front panel portion 97 in a stateof forming the outer fold 56 and the inner fold 57 in manufacturing theairbag 25. Further, in the left panel portion 99 (left wall portion 31),on a part near the inner region 59 in a general rear region 31 bdisposed behind the tack portion 54 (the portion disposed continuouslyfrom the inner region 59 in the left panel portion 99), slit-shapedinsertion holes 63 into which the respective regulating belt portions 65can be inserted are formed (see FIG. 10 and FIG. 13A). Specifically, theinsertion holes 63 are formed at two locations above and below theopening forming portion 52 at positions near the rear end of the openingforming portion 52 and on the front side of the rear edge 52 d of theopening forming portion 52. Further, the insertion holes 63 are formedto be substantially along the outer fold 56 and the inner fold 57 atpositions substantially symmetric with the outer fold 56 with the innerfold 57 as a center (positions close to the outer fold 56 when formingthe outer fold 56) (see FIGS. 10 to 11B),

The regulating belt portion 65 is formed of a belt-shaped body separatefrom the bag body 26. In the case of the embodiment, the regulating beltportions 65 are disposed around the opening portion 51 at two locationson both sides of a direction (sides in the upper-lower direction) alongthe outer fold 56 and the inner fold 57 of the tack portion 54, that is,at two locations on the upper side and the lower side of the openingportion 51 (see FIGS. 11A and 11B). As shown in FIGS. 10 to 11B, a baseend 65 a side of each regulating belt portion 65 is coupled to an outerregion 61 side of the tack portion 54, and the regulating belt portion65 is disposed to be substantially orthogonal to the outer fold 56 andthe inner fold 57. Then, the tip end 65 b side inserted into the airbag25 is coupled to a side (a position on the front side) of the airbag 25that is further away from a part coupled to the base end 65 a in a statewhere the regulating belt portion 65 is in an inverted state so as tosurround the tack portion 54 such that each regulating belt portion 65is inserted into the insertion hole 63 formed on the rear side of thetack portion 54 on the left wall portion 31. Specifically, the tip end65 b of each regulating belt portion 65 protrudes from the insertionhole 36 formed on the front end 27 a side of the body inflation portion27 in the bag body 26, and is locked to the locking member 16 providedon the case 12. A locking hole 66 capable of making the locking pin 17of the locking member 16 pass through is formed at the tip end 65 b ofeach regulating belt portion 65. That is, in the embodiment, eachregulating belt portion 65 is a part extending from the base end 65 a tothe insertion hole 63, and an outer peripheral side part 68 disposed onan outer peripheral surface side when the inflation is completed isdisposed to be substantially orthogonal to the outer fold 56 and theinner fold 57, an inverted part 69 inserted into the insertion hole 63is inverted, and a part from the inverted part 69 to the tip end 65 b isdisposed to extend forward as an inner peripheral side part 70 disposedon the inner peripheral surface side when the inflation is completed(see FIG. 10). Further, in the case of the embodiment, a coupling part67 that couples the base end 65 a side of the regulating belt portion 65to the outer region 61 is formed in the region on the outer fold 56 side(rear side) of the outer region 61 (see FIG. 11A). The base end 65 a ofthe regulating belt portion 65 is not limited to the outer region 61,and may be coupled to a region (in the left wall portion 31, the generalfront region 31 a disposed on the front side of the outer region 61)near the outer region 61 in the left panel portion 99.

In the embodiment, the two regulating belt portions 65, 65 are formed ofa single base material 72 for a belt (see FIG. 9) connected on the tipend 65 b side, and the tip end side is locked to the locking member 16in a state of being double-folded. The length dimension of eachregulating belt portion 65 is set to a. dimension capable of maintainingthe folded state of the tack portion 54 and stably maintaining theclosed state of the opening portion 51 (opening portion 51S in smallopen state) by a tension generated when the airbag 25 is inflatablewithout hindrance and the inflation thereof is completed, even when theairbag 25 is inflated in a state where the locking pin 17 is insertedinto the locking hole 66 and the locking with the locking pin 17 ismaintained. In the airbag device M according to the embodiment, when theairbag 25 is inflated in the closed mode in which the locking betweenthe regulating belt portion 65 and the locking member 16 is maintained,the airbag 25 is inflated with the opening portion 51S being in thesmall open state when the folded state of the tack portion 54 in thedischarge portion 50 is maintained (see FIGS. 13A and 14A). Further,when the airbag 25 is inflated in the open mode in which the lockingbetween the regulating belt portion 65 and the locking member 16 isreleased, the airbag 25 is inflated with the opening portion 51L beingin the large open state when the folded state of the tack portion 54 inthe discharge portion 50 is released (see FIGS. 13B and 14B).

As shown in FIG. 5, the rectifying cloth 74 disposed in the bag body 26covers the upper part of the inflow opening 34 and has a substantiallycylindrical shape with left and right sides opened, and is configured tomake the inflation gas flowing into the bag body 26 flow from the inflowopening 34 toward the left-right direction temporarily. The rectifyingcloth 74 includes a base material 75 for a rectifying cloth shown inFIG. 8.

As shown in FIGS. 5 to 7, as tethers for regulating the inflationcompleted shape of the bag body 26 in the bag body 26, a front-reartether 77, left and right tethers 83, 84, and a tether 90 for a recessare provided in the region of the body inflation portion 27 in the caseof the embodiment.

The front-rear tether 77 connects the substantially center in theleft-right direction of the front collision restraint surface 43 (rearside wall portion 40) and the front end 27 a side of the body inflationportion 27, and as shown in FIGS. 5 and 7, the front-rear tether 77 isconfigured to connect a front part 78 extending from the peripheral edgeof the inflow opening 34 to a rear part 79 extending from a rear sidewall portion 40 side. The front part 78 is formed by folding a basematerial 81 for a front part shown in FIG. 8, and the outer shape whenthe inflation of the bag body 26 is completed is a three-dimensionalshape approximating a substantially triangular pyramid shape in which afront end side is substantially along the left-right direction and arear end side is substantially along the upper-lower direction. The rearpart 79 is formed of a substantially trapezoidal sheet body in which afront end side connected to the front part 78 has a narrow width andexpands up and down toward a rear end side connected to the rear sidewall portion 40, and a rear end side is connected to a positionsubstantially at the center in the upper-lower and left-right directionsof the rear side wall portion 40.

When the inflation of the airbag 25 is completed, the front-rear tether77 connects the approximately center in the left-right direction of therear side wall portion 40, that is, a substantially center in theleft-right direction of the front collision restraining surface 43, tothe peripheral edge part of the inflow opening 34 (the front end 27 aside of the body inflation portion 27), and the front-rear tether 77 isdisposed in order to prevent the front collision restraining surface 43(rear side wall portion 40) from excessively protruding rearward in aninitial inflated stage of the airbag 25, and to prevent the rearwardmovement of the front collision restraint surface 43 when the inflationin completed. Further, in the embodiment, the rear side wall portion 40is pulled by the front-rear tether 77, so that when the inflation of theairbag 25 is completed, the substantially center in left-right directionof the rear side wall portion 40 is slightly recessed toward the vehiclefront side over substantially the entire upper-lower region (see FIG.7).

In the case of the embodiment, the left and right tethers 83, 84 aredisposed at two locations, that is, above and below the front-reartether 77 as shown in FIGS. 5 and 6, connect the parts near the rearends of the left wall portion 31 and the right wall portion 32respectively, and are provided substantially along the left-rightdirection when the inflation of the bag body 26 is completed. The leftand right tethers 83, 84 are provided in a region behind the dischargeportion 50 (tack portion 54). The left and right tethers 83, 84 includetwo strip-shaped base materials 86L, 86R, 87L, 87R for a tether,respectively (see FIG. 9). The left and right tethers 83, 84 areprovided to suppress excessive expansion of the airbag 25 to the leftand right in the initial inflated stage and to regulate the widthdimension in the left-right direction of the airbag 25 (a separationdistance between the left wall portion 31 and the right wall portion 32)when the inflation is completed.

As shown in FIG. 7, when the inflation of the airbag 25 is completed,the tether 90 for a recess is configured to connect the recessed tip end(front end 45 a) side of the restraining recess 45 to the front end side(front end 27 a side of the body inflation portion 27) of the airbag 25.In the case of the embodiment, as shown in FIG. 7, the tether 90 for arecess is configured to connect a front part 91 extending from theperipheral edge of the inflow opening 34 to a rear part 92 extendingfrom the restraining recess 45 side. Similar to the front part 78 in thefront-rear tether 77, the front part 91 is formed by folding a basematerial 94 for a front part as shown in FIG. 8, and the outer shapewhen the inflation of the bag body 26 is completed is athree-dimensional shape approximating a substantially triangular pyramidshape in which the front end side is substantially along the left-rightdirection and the rear end side is substantially along the upper-lowerdirection. The rear part 92 is formed of a substantially trapezoidalsheet body in which a front end side connected to the front part 91 hasa narrow width and expands up and down toward a rear end side connectedto the restraining recess 45, and the rear end side is connected to afront end side of the restraining recess 45. In the case of theembodiment, the rear part 92 includes extending portions 107 b, 110 bformed to extend from parts 107, 110 for a recess formed in a rear leftpanel portion 105 and a rear center panel portion 109 respectively,which will be described below (see FIGS. 6 and 8). The tether 90 for arecess is inclined with respect to the front-rear direction such that afront end 90 a side is located at the right side and a rear end 90 bside is located at the left side when the inflation of the airbag 25 iscompleted (see FIG. 7). The tether 90 for a recess is set to such alength dimension that the restraining recess 45 can be pulledsubstantially forward along the tether 90 for a recess when theinflation of the airbag 25 is completed.

The bag body 26 is formed in a bag shape by coupling peripheral edges ofa base cloth having a predetermined shape to each other, and in the caseof the embodiment, includes a left panel portion 99, a right panelportion 102, a front panel portion 97, a rear left panel portion 105, arear center panel portion 109, and a rear right panel portion 112 asshown in FIGS. 8 and 9.

The front panel portion 97 has an outer shape of a substantially stripshape with a longitudinal direction substantially along the front-reardirection, and is configured such that a front end side and a rear endside in a flatly unfolded state are widened toward end edge sides (rearupper edge 97 a, rear lower edge 97 b), respectively. The front panelportion 97 is configured to extend from the upper wall portion 29 to thelower wall portion 30 that face each other in the upper-lower directionin the body inflation portion 27 when the inflation is completed. In thecase of the embodiment, the front panel portion 97 is symmetrical.

The left panel portion 99 is configured to extend from the left wallportion 31 to the left wall portion 41 a of the protruding inflationportion 41 in the body inflation portion 27 when the inflation iscompleted, and a region on a rear end side thereof is a protrudingportion forming portion 100 that forms the left wall portion 41 a of theprotruding inflation portion 41. In the case of the embodiment, a rearedge 99 c of the left panel portion 99 is formed such that a lowerregion thereof is gently inclined from the lower edge 99 b. At aposition slightly in front of the center in the front-rear direction andsubstantially at the center in the upper-lower direction of the leftpanel portion 99, as described above, the opening forming portion 52that forms the opening portion 51 of the discharge portion 50 is formedin an oval shape substantially along the front-rear direction. The leftpanel portion 99 is configured such that, when the tack portion 54 isformed, the outer shape of the front region excluding the protrudingportion forming portion 100 is substantially the same as the right panelportion 102. The right panel portion 102 forms the right wall portion 32of the body inflation portion 27.

The rear left panel portion 105 is formed in a substantially strip shapethat forms a part on the left edge side of the rear side wall portion 40in the body inflation portion 27 when the inflation is completed, andpartially protrude a protruding portion forming portion 106 forming theright wall portion 41 b of the protruding inflation portion 41 and apart 107 for a recess forming the left wall portion 46 of therestraining recess 45. Specifically, the protruding portion formingportion 106 is formed so as to protrude from a left edge 105 c of therear left panel portion 105 in a flatly unfolded state, and the part 107for a recess is formed so as to protrude from a right edge 105 d. Theextending portion 107 b forming the rear part 92 of the tether 90 for arecess is disposed on a tip end side of the part 107 for a recess.

The rear center panel portion 109 forms a region on the left side of thecenter in the left-right direction of the rear side wall portion 40, andis configured as a strip shape whose longitudinal direction issubstantially along the upper-lower direction. A part 110 for a recessforming the right wall portion 47 of the restraining recess 45 is formedon a left edge 109 c of the rear center panel portion 109 so as toprotrude. The extending portion 110 b forming the rear part 92 of thetether 90 for a recess is disposed on a tip end side of the part 110 fora recess. The rear right panel portion 112 forms a region on the rightside of the center in the left-right direction of the rear side wallportion 40, and is configured as a strip shape whose longitudinaldirection is substantially along the upper-lower direction.

In the airbag 25 according to the embodiment, a substantially circularreinforcing cloth 115 is provided in a peripheral edge region of theopening portion 51 (see FIGS. 3, 9 14A and 14B). In the embodiment, thefront panel portion 97, the left panel portion 99, the right panelportion 102, the rear left panel portion 105, the rear center panelportion 109, the rear right panel portion 112, the reinforcing cloth115, the base material 72 for a base, the base material 75 for arectifying cloth, the front part 78 (base material 81 for a front part)of the front and rear tethers 77, the rear part 79, the front part 91(base material 94 for a front part) of the tether 90 for a recess, andthe base materials 86L, 86R, 87L, 87R for a tether of the left and righttethers 83, 84 forming the bag body 26 are each formed of a flexiblewoven cloth made of polyester yam, polyamide yam, and the like.

As shown in FIGS. 3 to 9, the bag body 26 according to the embodiment isformed in a bag shape having the discharge portion 50 by sewing(coupling) the corresponding edge portions of the front panel portion97, the left panel portion 99, the right panel portion 102, the rearleft panel portion 105, the rear center panel portion 109, and the rearright panel portion 112 using a suture thread.

Specifically, the rear upper edge 97 a of the front panel portion 97 iscoupled to upper edges 105 a, 109 a, 112 a of the rear left panelportion 105, the rear center panel portion 109, and the rear right panelportion 112, and the rear lower edge 97 b is coupled to lower left edges105 b, 109 b, 112 b of the rear left panel portion 105, the rear centerpanel portion 109, and the rear right panel portion 112. The left edge97 c of the front panel portion 97 is coupled from the upper edge 99 ato the lower edge 99 b of the left panel portion 99, and the right edge97 d is coupled from ⁻the upper edge 102 a to the lower edge 102 b ofthe right panel portion 102. The rear edge 99 c of the left panelportion 99 is coupled to a left edge of the rear left panel portion 105and an outer edge 106 a of the protruding portion forming portion 106. Arear edge of the right panel portion 102 is coupled to a right edge 112d of the rear right panel portion 112. The right edge 105 d of the rearleft panel portion 105 is coupled to the left edge 109 c of the rearcenter panel portion 109, and at this time, outer edges 107 a, 110 a ofthe parts 107, 110 for a recess are also coupled to each other. A rightedge 109 d of the rear center panel portion 109 is coupled to a leftedge 112 c of the rear right panel portion 112.

Next, mounting of the airbag device M according to the embodiment on thevehicle V will be described. First, the airbag 25 is folded so as to becapable of being stored in the case 12 in a state where the retainer 9is stored therein, and the folded airbag 25 is wrapped by a breakablewrapping sheet (not shown) for preventing folding collapse. At thistime, the tip end 65 b side of the regulating belt portion 65 extendingfrom the discharge portion 50 protrudes from the insertion hole 36formed on the bag body 26. Thereafter, the folded airbag 25 is stored inthe case 12 to which the locking member 16 has been attached in advanceso as to protrude the bolt 9 a from the bottom wall portion 13. Then,the tip end 65 b side of the regulating belt portion 65 is locked to thelocking member 16 such that the locking pin 17 of the locking member 16is inserted into the locking hole 66 on the tip end 65 b side of theregulating belt portion 65 protruding from the through hole 13 b formedon the bottom wall portion 13 and the tip end of the locking pin 17 issupported by the support bracket 19. Next, the body portion 8 a of theinflator 8 is inserted into the case 12 from below the bottom wallportion 13, and the bolts 9 a of the retainer 9 protruding downward fromthe bottom wall portion 13 are inserted through the flange portion 8 cof the inflator 8. Thereafter, if the nut 10 is fastened to each bolt 9a protruding from the flange portion 8 c of the inflator 8. the foldedairbag 25 and the inflator 8 can be attached to the case

Then, the airbag device M can be mounted on the vehicle by locking theperipheral wall portion 14 of the case 12 to the connecting wall portion6 c of the airbag cover 6 in the instrument panel 1 mounted on thevehicle V, fixing a bracket (not shown) provided in the case 12 to thebody side of the vehicle V, and electrically connecting the inflator 8and the locking member 16 to the control device 120.

In the airbag device M according to the embodiment, if the frontalcollision, the oblique collision, or the offset collision of the vehicleV is detected when the airbag M is mounted on the vehicle V, the controldevice 120 outputs the operation signal to the inflator 8, the inflator8 discharges the inflation gas from the gas discharge ports 8 b, and theairbag 25 is inflated by making the inflation gas flow therein, andpushes to open the door portions 6 a, 6 b of the airbag cover 6. Then,the airbag 25 protrudes upward from the case 12 through an openingformed by pushing to open the door portions 6 a, 6 b of the airbag cover6, and unfolds and inflates while protruding toward a rear side of thevehicle V. As shown by a two-dot chain line in FIG. 1 and FIGS. 12 and14, the airbag 25 is completely inflated so as to fill the space betweenthe upper surface 2 of the instrument panel 1 and the windshield 4 abovethe instrument panel 1.

In the airbag device M according to the embodiment, in the dischargeportion 50, as shown in FIG. 13A, since the regulating belt portion 65having the base end 65 a side coupled to the outer surface side of theairbag 25 (the body inflation portion 27) is in the inverted state so asto surround the periphery of the tack portion 54 provided around theopening portion 41, and the tip end 65 b side inserted into the airbag25 is connected to the airbag 25 side, when the inflation of the airbag25 is completed, the regulating belt portion 65 is disposed so as togenerate tension T toward a direction side in which the folding of theinner fold 57 is not unfolded, and the folded state of the tack portion54 can be maintained by the regulating belt portion 65. Specifically, inthe airbag device according to the embodiment, by the regulating beltportion 65 disposed so as to generate the tension T toward the directionside in which the folding of the inner fold 57 is not unfolded when theinflation of the airbag 25 is completed, it is difficult to unfold thefold of the inside fold 57, the inner region 59 and the intermediateregion 60 in the tack portion 54 can be brought into smoothly closecontact with the outer region 61 by receiving the internal pressure ofthe inflation gas flowing into the airbag 25, and thus the folded stateof the tack portion 54 forming the discharge portion 50 can bemaintained, and good sealing properties can be ensured. Therefore, asshown in FIG. 14A, the closed state (small open state) of the openingportion 51 can be stably maintained, and a predetermined internalpressure of the airbag 25 at the time of inflation can be stablyensured. Incidentally, a related-art airbag 25′ having a configurationin which a tip end side of a regulating belt portion 65′ is disposed tobe separated from a base portion 65 a side and a tack portion 54′ isdescribed as a comparative example in FIG. 16. In the airbag 25′ havingsuch a configuration, when the tension T is generated in the regulatingbelt portion 65′ at the time of completion of the inflation, theregulating belt portion 65′ behaves in a manner of pulling inward a partof an inner fold 57′ disposed on an inner peripheral surface side of theairbag 25′ in the tack portion 54′ so as to separate the part of theinner fold 57′ from an outer region 61′. Therefore, even if the tackportion 54′ receives the internal pressure of the inflation gas flowinginside, an inner region 59′ and an intermediate region 60′ are pulled bythe regulating belt portion 65′ and behave as if the inner region 59′and the intermediate region 60′ are peeled off from an outer region 61′disposed on an outer peripheral surface side, and the opening portion51′ cannot be stably closed by the tack portion 54′. in the airbagdevice M according to the embodiment, when the tension of the regulationbelt portion 65 is not applied, the airbag device M receives a pressingforce of the inflation gas flowing into the airbag 25, the folded stateof the tack portion 54 due to the outer fold 56 and the inner fold 57 isquickly released (see FIG. 13B), the opening portion 51 is in an openstate (large open state) (see FIG. 14B), and the inflation gas is stablyexhausted.

Therefore, in the airbag device M according to the embodiment, theinternal pressure of the airbag 25 at the time of completion of theinflation can be accurately controlled by the discharge portion 50.

In the airbag device M according to the embodiment, since the regulatingbelt portions 65 are provided around the opening portion 51 at twolocations on both sides of the direction along the outer fold 56 and theinner fold 57 of the tack portion 54, that is, two locations on theupper side and lower side of the opening portion 51 in the case of theembodiment, when the inflation of the airbag 25 is completed, the foldedstate due to the outer fold 56 and the inner fold 57 of the tack portion54 can he more stably maintained by the two regulating belt portions 65.If such a point is not taken into consideration, the regulating beltportion may be disposed at only one location.

Further, in the airbag device M according to the embodiment, the openingforming portion 52 forming the opening portion 51 is provided across theinner fold 57 and the outer fold 56, and as shown in FIG. 14A, theopening portion 51 has an opening as the small open state even in theclosed state. Therefore, in the airbag device M according to theembodiment, the opening portion 51S can also be used as a vent hole forexhausting excess inflation gas flowing inside by being opened even inthe closed state, and a vent hole may not be separately provided. In theembodiment, the opening portion 51S in the small open state has anopening area set to be substantially the same as the vent hole 37provided in the right wall portion 32, and is configured to exhaustexcess inflation gas in the closed state. It goes without saying that ifsuch points are not taken into consideration, the opening portion of theairbag may be configured to be brought into the closed state in theclosed state and a separate vent hole may be provided.

Further, in the airbag device M according to the embodiment, the tip end65 b side of the regulating belt portion 65 is locked to the lockingmember 16 disposed on the case 12 side in a state of protruding outsidethe airbag 25, and the locking member 16 is configured to be capable ofreleasing the locked state of the tip end portion 65 b side of theregulating belt portion 65 by operating the actuator 18. Therefore,operating time of transiting the opening portion 51 to the open statecan be made substantially constant by operating the actuator 18, so thatthe protection performance of the airbag 25 is unlikely to vary, and theoccupant MP can be stably protected.

Specifically, in the airbag device M according to the embodiment, theactuator 18 of the locking member 16 that locks the tip end 65 b side ofthe regulating belt portion 65 extending from the discharge portion 50is controlled in operation by the control device 120. In a case wherethe control device 120 that inputs signals from the predeterminedsensors 121, 122, and 123 detects, for example, the sitting of asmall-sized occupant MP1 or the sitting of the occupant MP at a positionclose to the instrument panel 1, the control device 120 outputs anoperation signal to the actuator 18 of the locking member 16 atsubstantially the same time as the operation of the inflator 8, and thelocking member 16 is operated to pull in the locking pin 17. Then, asshown in FIG. 14B, the folded state of the tack portion 54 is released,and the airbag 25 is inflated in the open mode in which the openingportion 51L is brought into the large open state, and the inflation iscompleted by exhausting excess inflation gas G from the opening portion51L in the large open state. Therefore, since the airbag 25 exhausts theexcess inflation gas G from the opening portion 51L and completes theinflation in a state where an increase in the internal pressure issuppressed, the airbag 25 whose internal pressure is set to be low cansuppress overly pressing the small-sized occupant MP1 and the occupantMP sitting close to the instrument panel 1, thereby softly protectingthe small-sized occupant MP1 and the occupant MP.

On the contrary, when the control device 120, for example, detects thata large-sized occupant MP2 sits or that the occupant MP sits at aposition away from the instrument panel 1, the operation signal is notoutput from the control device 120 to the actuator 18, the airbag 25 isinflated in a closed mode in which the opening portion 51S is broughtinto the small open state while the folded state of the tack portion 54is maintained by the tension generated in the regulating belt portion65, and the small open state is maintained until the inflation iscompleted as shown in FIG. 14A. The opening portion 51S in the smallopen state acts as a vent hole normally provided in the airbag, and theexhaust amount of the inflation gas is suppressed. Thus, the airbag 25completes the inflation in a state where the internal pressure is high,and ensures a sufficient internal pressure for the large-sized occupantMP2 and the occupant MP who sits away from the instrument panel 1, andthe airbag 25 that has been inflated with good cushioning properties canbe properly protected without bottoming.

Note that the tip end of the regulating belt portion does not need to belocked to the locking member, and for example, like an airbag 25A shownin FIGS. 15A and 15B, the tip end 65 b of a regulating belt portion 65Aextending from a discharge portion 50A is connected (sewing) to aposition on the inner peripheral surface side of the bag body 26A thatis further away from the part where the base end 65 a is connected(front side in the case of the embodiment), and when the occupant MP isreceived by a front collision restraint surface 43A at the time ofcompletion of the inflation, the regulating belt portion 65A may be ableto be loosened as shown in FIG. 15B. Specifically, in the airbag 25A,when the discharge portion 50A for discharging the inflation gas isdisposed near the rear end of a left wall portion 31A, and the occupantis received by a front collision restraint surface 43A, with the frontcollision restraint surface 43A moving forward, the left wall portion31A bends so as to reduce the width dimension in the front-reardirection, the regulating belt portion 65A is loosened due to thebending of the left wall portion 31A, and the opening portion of thedischarge portion 50A is brought into the open state, so that excessinflation gas is exhausted.

Further, in the airbag device according to the embodiment, since theouter fold 56 and the inner fold 57 forming the tack portion 54 areformed so as to extend toward outer peripheral edge sides (an upper edge99 a side and a lower edge 99 b side) of the left panel portion 99 asthe base material forming the airbag 25, the outer shape of the tackportion 54 can be stabilized as compared with the case where the tackportion is partially provided on the base material. It goes withoutsaying if such a point is not taken into consideration, the tack portionmay not be provided over the entire region of the left panel portion(left wall portion).

In the embodiment, the airbag device for a passenger seat is adopted asan example and described, but the airbag device to which the presentinvention can be applied is not limited to the airbag device for apassenger. For example, the present invention is also applicable to anairbag device for a steering wheel disposed in front of a driver as anoccupant, an airbag device disposed in front of an occupant sitting in arear seat, and the like.

According to an aspect of the invention, there is provided an airbagdevice comprising: an airbag folded and stored in a storage part,configured to inflate so as to protrude from the storage part byallowing inflation gas to flow inside, the airbag formed with adischarge portion capable of discharging a part of the inflation gasflowing into the airbag, wherein the discharge portion includes: anopening portion formed by cutting out a base material forming theairbag; a tack portion provided on the base material around the openingportion; and a regulating belt portion separated from the airbag anddisposed on a peripheral edge of the opening portion to regulate openingand closing of the opening portion, the tack portion is formed by makinga fold on the base material from a state where the base material isflatly unfolded so as to reduce an opening area of an opening on theopening portion, the tack portion is formed by folding the base materialby an outer fold and an inner fold that which are formed substantiallyin parallel, such that an inner region, an intermediate region, and anouter region are stacked, a base end side of the regulating belt portionis coupled to an outer region side, the regulating belt portion isdisposed to be substantially orthogonal to the outer fold and the innerfold, and a tip end side inserted into the airbag is connected to a sideof the airbag which is further away from a part coupled to the base endin a state where the regulating belt portion is in an inverted state soas to surround the tack portion such that the regulating belt portion isinserted into an insertion hole formed on a part of the base materialdisposed continuously from the inner region, and when the inflation ofthe airbag is completed, the tack portion is maintained in a foldedstate by the regulating belt portion due to tension acting on theregulation belt portion, so that a closed state of the opening portionis capable of being maintained, and when the tension does not act on theregulating belt portion, the folded state is released and the openingportion is brought into an open state.

In the airbag device according to the present invention, in thedischarge portion, since the regulating belt portion having the base endside coupled to the outer surface side of the airbag is in the invertedstate so as to surround the periphery of a tack portion provided aroundthe opening portion, and the tip end side inserted into the airbag isconnected to the airbag side, when the inflation of the airbag iscompleted, the regulating belt portion is disposed so as to generatetension toward a direction side in which the folding of the inner foldis not unfolded, and the folded state of the tack portion can bemaintained by the regulating belt portion. Specifically, in the airbagdevice according to the present invention, by the regulating beltportion disposed so as to generate the tension toward the direction sidein which the folding of the inner fold is not unfolded when theinflation of the airbag is completed, it is difficult to unfold the foldof the inside fold, the inner region and the intermediate region in thetack portion can be brought into smoothly close contact with the outerregion by receiving the internal pressure of the inflation gas flowinginto the airbag, and thus the folded state of the tack portion formingthe discharge portion can be maintained, and good sealing properties canbe ensured. Therefore, the closed state of the opening portion can bestably maintained, and a predetermined internal pressure of the airbagat the time of inflation can be stably ensured. Further, in the airbagdevice according to the present invention, when the tension of theregulation belt portion is not applied, the airbag device receives apressing force of the inflation gas flowing into the airbag, the foldedstate of the tack portion due to the outer fold and the inner fold isquickly released, the opening portion is in an open state, and theinflation gas is stably exhausted.

Therefore, in the airbag device according to the embodiment, theinternal pressure of the airbag when the inflation is completed can beaccurately controlled by the discharge portion.

In the airbag device according to the present invention, if theregulating belt portions are provided around the opening portion at twolocations on both sides of the direction along the fold of the tackportion, when the inflation of the airbag is completed, it is preferablethat the folded state due to the outer fold and the inner fold of thetack portion can be more stably maintained by the two regulating beltportions.

Further, in the airbag device according to the present invention, if theopening portion is provided across the inner fold and the outer fold andhas an opening even when the opening portion is in the closed state, itis preferable that the opening portion can also be used as a vent holefor exhausting excess inflation gas flowing inside by being opened evenin the closed state, and a vent hole may not be separately provided.

Further, in the airbag device with the above configuration, it ispreferable that the tip end side of the regulating belt portion islocked to a locking member disposed on a storage part side in a state ofprotruding outside the airbag, and the locking member is configured tobe capable of releasing the locked state of the tip end side of theregulating belt portion by operating an actuator.

If the airbag device has such a configuration, operating timing oftransiting the opening portion to the open state can be madesubstantially constant by operating the actuator, so that the protectionperformance of the airbag is unlikely to vary, and the occupant can bestably protected.

Further, in the airbag with the above configuration, the regulating beltportion may be configured such that the opening portion is brought intothe open state when the occupant is received by the airbag whoseinflation is completed.

Further, in the airbag device with the above configuration, if the outerfold and the inner fold forming the tack portion are formed so as toextend toward outer peripheral edge sides of the base material formingthe airbag, the outer shape of the tack portion can be stabilized ascompared with the case where the tack portion is partially provided onthe base material.

1. An airbag device comprising: an airbag folded and stored in a storagepart, configured to inflate so as to protrude from the storage part byallowing inflation gas to flow inside, the airbag formed with adischarge portion capable of discharging a part of the inflation gasflowing into the airbag, wherein the discharge portion includes: anopening portion formed by cutting out a base material forming theairbag; a tack portion provided on the base material around the openingportion; and a regulating belt portion separated from the airbag anddisposed on a peripheral edge of the opening portion to regulate openingand closing of the opening portion, the tack portion is formed by makinga fold on the base material from a state where the base material isflatly unfolded so as to reduce an opening area of an opening on theopening portion, the tack portion is formed by folding the base materialby an outer fold and an inner fold that which are formed substantiallyin parallel, such that an inner region, an intermediate region, and anouter region are stacked, a base end side of the regulating belt portionis coupled to an outer region side, the regulating belt portion isdisposed to be substantially orthogonal to the outer fold and the innerfold, and a tip end side inserted into the airbag is connected to a sideof the airbag which is further away from a part coupled to the base endin a state where the regulating belt portion is in an inverted state soas to surround the tack portion such that the regulating belt portion isinserted into an insertion hole formed on a part of the base materialdisposed continuously from the inner region, and when the inflation ofthe airbag is completed, the tack portion is maintained in a foldedstate by the regulating belt portion due to tension acting on theregulation belt portion, so that a closed state of the opening portionis capable of being maintained, and when the tension does not act on theregulating belt portion, the folded state is released and the openingportion is brought into an open state.
 2. The airbag device according toclaim 1, wherein the regulating belt portion includes regulating beltportions which are provided around the opening portion, and at twolocations on both sides of a direction along the fold of the tackportion.
 3. The airbag device according to claim 1, wherein the openingportion is provided across the inner fold and the outer fold and has anopening even when the opening portion is in the closed state.
 4. Theairbag device according to claim 1, wherein the tip end side of theregulating belt portion is locked to a locking member disposed on astorage part side in a state of protruding outside the airbag, and thelocking member is configured to be capable of releasing a locked stateof the tip end side of the regulating belt portion by operating anactuator.
 5. The airbag device according to claim 1, wherein theregulating belt portion is configured to bring the opening portion intothe open state when the occupant is received by the airbag that iscompletely inflated.
 6. The airbag device according to claim 1, whereinthe outer fold and the inner fold forming the tack portion are formed soas to extend toward an outer peripheral edge of the base materialforming the airbag.